1. Field of the Invention
The present invention relates to an objective lens with improved moldability and an optical pickup apparatus using the same. The present invention also relates to a method for manufacturing such an objective lens.
2. Description of the Related Art
An objective lens formed by molding a glass or plastic material into a predetermined shape with a mold has been conventionally used for reading and writing of information from and to an optical disc.
In a method for manufacturing an objective lens formed of a plastic material disclosed in Japanese Patent Application Publication 2007-196665, with reference to FIG. 2, a description thereof, and other part, a mold including mold portions 11 and 12 is prepared and a resin material is injected into the mold to form the objective lens having a predetermined shape. The mold portions 11 and 12 have inner wall shapes conforming to lens surface shapes of the objective lens to be molded.
To reduce the number of parts required in an optical pickup apparatus, a compatible lens has been developed that focuses laser beams of a plurality of standards on corresponding optical discs. For example, a compatible objective lens has been developed that focuses laser beams of a blu-ray disc (BD) standard, a digital versatile disc (DVD) standard, and a compact disc (CD) standard on optical discs of corresponding standards.